Data from: MHC class II supertypes affect survival and lifetime reproductive success in a migratory songbird
Data files
Apr 03, 2025 version files 122.86 KB
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CMRdata.txt
72.96 KB
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LRSdata.txt
47.70 KB
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README.md
2.20 KB
Abstract
The major histocompatibility complex (MHC) plays a critical role in the immune response against pathogens. Its high polymorphism is thought to be mainly the consequence of host-pathogen co-evolution, but elucidating the mechanism(s) driving MHC evolution remains challenging for natural populations. We investigated the diversity of MHC class II genes in a wild population of pied flycatchers Ficedula hypoleuca, and tested its associations with two key components of individual fitness: lifetime reproductive success and survival. Among 180 breeding adults in our study population, we found 182 unique MHC class II exon 2 alleles. The alleles showed a strong signal of positive selection and grouped into 9 functional supertypes based on physicochemical properties at the inferred antigen-binding sites. Three supertypes were found in > 98% of the sampled individuals, indicating that they are nearly fixed in the population. We found no rare supertypes in the population, as all supertypes were present in >70% of individuals. Three supertypes were related to different components of individual fitness: two were associated with lower offspring production over time, while the third was positively associated with survival. Overall, the substantial allelic and functional diversity and the relationship between specific supertypes and fitness is in accordance with the notion that balancing selection maintains MHC class II diversity in the study population, possibly with fluctuating selection as the underlying mechanism. The absence of rare supertypes in the population suggests that the balancing selection is not driven by rare-allele advantage.
https://doi.org/10.5061/dryad.0p2ngf297
Description of the data and file structure
DATA USAGE
The data are supplied by the authors with the request that future users of the data are aware that the monitoring of the pied flycatcher population is an ongoing research program, so authors should be advised of the use of the data to avoid potential conflicts.
During the analyses data were organized in two datasets:
1. Analyses on lifetime reproductive success: LRSdata.txt
2. Survival analyses: CMRdata.txt
Files and variables
File: LRSdata.txt
Description: Dataset used for analyses on life timer reproductive success
Variables
- ring: individual identity
- sex: male or female
- habitat: oak or pine forest
- yearBorn: year of born of the individual
- LRSf: Total number of fledglings produced over an individual’s lifetime
- NumSTypes: Total number of supertypes that the individual has
- Num_MHCAlleles: Total number of alleles that the individual has
- ST1 to ST9: Whether or not the individual has each of the nine supertypes found in the population
- Al_001 to Al_182: Whether or not the individual has each of the 182 alleles found in the population
File: CMRdata.txt
Description: Dataset used for the survival analyses
Variables
- ch: capture history
- ring: individual identity
- habitat: oak or pine forest
- sex: male or female
- yearBorn: year of born of the individual
- ageRec: age at the first breeding attempt
- NumSTypes: number of supertypes that the individual has
- Num_MHCAlleles: number of alleles that the individual has
- HL: homozygosity by loci based on 15 microsatellites. See Aparicio et al., 2006. Molecular Ecology, 15(14), 4659–4665.
- ST1 to ST9: Whether or not the individual has each of the nine supertypes found in the population
- Al_001 to Al_182: Whether or not the individual has each of the 182 alleles found in the population
Code/software
Code used during analyses are given the in the supplementary file of the associated article